Process of making cheese



Patented Mar. 6, 1945 2.3mm V raocsss or MAKING cimnss Zola D. Ronmly, Chitin, and Havard L. Kell, Clarendon Hills. 111., assignors to Armour and Company, Chicago, Ill., nols a corporation oi llll- No Drawing. Application October 16, 1942, Serial No. 462,308

9 Claims. ((1. es -1m) This invention relates to methods of making cheese and involves processes in which proteolytic enzymes, particularly tryptic enzymes are employed for producing development of body characteristics.

This application is a continuation in part of our copending application Serial No. 288,190, filed August 3, 1939, now abandoned, and is in some respects an improvement on the invention set forth in our copending application Serial No. 275,554, filed May 24, 1939, now abandoned. In Serial No. 275,554 we describe a. process in which the functions ordinarily associated with aging are speeded up and controlled so as to produce in a relatively short time a cheese product having all the qualities normally assigned to our aged cheese. The aging process is speeded up through the use of tryptic enzymes for attacking the curd and the activity of these enzymes is so controlled as to eliminate objectionable flavors and odors.

By the improvement of the present invention we employ tryptic enzymes in a changed procedure which gives rise to further advantages in the cheese-making art. In the improved procedure of this invention we treat the curd, preferably before drawing off the whey, to inhibit the activity of acid-forming organisms while still permitting the survival of the tryptic enzymes. In fact, the treatment we use has the eflect of enhancing or speeding up the activity of the enzymes.

In carrying out our process we add a lactic acid starter as in the usual procedure. This starter includes the acid-forming organisms which are heat-sensitive. Then we add the tryptic enzyme material and "set the milk with a coagulating agent, either rennin or pepsin, preferably rennin. at a temperature of about 84 F. to 88 F. The curd is next cut and cooked at the usual temperatures of 90 F. to 101" F.

In prior practices the whey is drained from the curd at the cooking stage and the curd thereafter cut in blocks. However, we heat the curd preferably in the presence of the whey to a point which will inhibit further action of acid-forming bacteria and at the same time enhance the action of the tryptic enzymes.

For convenience of description we use the term milk to designate the material acted upon through the treatment steps up to the point 01 coagulation, and use the term "milk material" to designate the material acted upon from the beginning of the process through coagulation to the stage where the curd body development is commeted.

The tryptic enzymes are the proteolytic enzymes of the animal pancreas which are com monly marketed under the name of Trypsin and sometimes called pancreatin. The material commonly known as trypsin or pancreatin contains as well as pure trypsin minor amounts of chymotrypsin, erepsin and other proteolytic enzymes. and amylopsin and steapsin, the amylopsin being a starch-splitting enzyme and the steapsin being the lypolytic or fat-splitting enzyme of the pancreas. By the terms "tryptic enzyme material or "tryptic material" as used herein. we mean the material above described commonly known as trypsin or any material of such type derived from animal pancreas and containing a proteolytic en- 'zyme. The term "tryptic enzymes is taken to include the proteolytic enzymes from animal pancreas.

The acid-forming organisms which are added in the lactic acid starter are Streptococcus lactis and associative organisms such as Streptococcus citrovorus and Streptococcus paracitrovorus. The temperatures we use in this heating step are sufllcient to give these acid-forming organisms severe heat shock so that further development is substantially prevented. Some of these acidformers are permanently destroyed by the heating step and most of them are put out of action by heat shock.

The heating step which serves in its one function for controlling the bacterial activity is especially important in view oi the fact that the curd which has been aflected by tryptic enzyme action makes a more favorable medium for the propagation of certain of these bacteria and it is only by the effect of the heating step that this eflect oi the tryptic enzymes can be dealt with effectively.

We find that the acid-forming bacteria are affected at temperatures above 106" F. The upper limit of temperature must be below that at which the tryptic enzymes are destroyed. Since these enzymes are destroyed at about 130 F., the upper limit of the temperatures which we can use is about 126 F. or 128' F. However, we prefer to use temperatures well within these limits, as 110 F. to F., since the use of temperatures as high as 110 F. insures adequate check on the organisms, and temperatures not higher than 120 F. insure against destruction of the enzymes. Though not all of the acid-forming bacteria are killed at temperatures within the range we employ. the practical effect is to substantially destroy further action of the organisms in developing acidity.

In addition to the function of limiting bacterial action. the heating step has the added advantage 2 acme-re or enhancing or stepping up the activity oi the is naturally included. but by substantially tree" tryptic enzymes. M the temperature is raised we mean the material used does not even contain these enzymes become more active lust below the a substantial portion of the steapsin normally temperature at which they are destroyed. contained in the common trypsin or pancreatin. Preierably the whey is still present during this s It is understood that while advantageous to use heating stage, and the mixture is held at the the'tryntic material whicliis substantially ree oi stated temperature for a few minutes, ior ext psln and to use the pepsin material in addiample, about 15 minutes. Then we draw the tion to the tryptic material. our invention is not whey from-the curd. Next th curd is allowed to a limited to the practice of these lectures. met and is t nt glabg which my be kept in in We shall now give a detailed example of how a cooler for about two days to a week. The our invention can be carried out without. howlength of this aging period may vary depending ever, limiting ourselves thereto. upon the temperature at which the um 1; kept, To 1000 pounds or milk we add about 1% ct a since. in general, higher temperatures permit of ic aci starter in the u l 1 9 h shorter aging periods. It is significant here also 15 milk. The. tryptic enzy material to be use is that by controlling the temperature at which the then added.

aglns takes place the period of aging may be con- The Q y h s ryp c m teri wi troiled to suit the convenience of the manupend in p rt upon the activity thereof. It should iacturer. preferably be added prior to coaeulation through The tryptic nzyme material is especially fl an action of rennin or pepsin since it rennin is added tive in producing the desired protein alteration first th milk on dies. makins it dii'iicult to inior developing body characteris ics. much more n r t t ryl tie enl m mstel' al- T eiiectively than proteolytic ensyne material from t pt enzy e material may be added in powder other sources. For this purpose pepsin, for exr liquid term and using t l quid solution we ample, will not sumce, but in our process pepsin 25 may add about 300 to 700 c. c. of a solution testmay be used to serve another quite important 8 by hod I tryp l strenl of function. so it is a further Ieature of our invention to use along with the tryptie enzyme When we use pepsin in addition to the tryptlc terlal a pepsin material. The pepsin material 13 a material we add about to ill grams or a derived from animal stomachs and contains the material prepared from animal stomachs ior each enzyme pepsin. when it is employed along with 1000 po ds r mi the p ps mat ri te tthe tryptic material somewhat better control can i1 8 by B- mBthOds a p p strenl f be eflected than where the tryptlc material is used 1:3000. alone. The amount oi the pepsin material which Aft r addins the tryp ic enzyme material we can be used is subject to much greater variation as then set t m pr ferably with rennin. ab ut than the mount 0! the tryptic material, and it to l" Th a unt of n n rms a seems that th combined ti of t enzyme, strength of about 1:5000 for about 8 ounces for contained in these materlflg it wider pm. each 1000 poimds of milk. Coagulltion occurs tude of conditions. For example. when the pepr p dly in the milk while at the settlns t p sin material is used along with the trypsin ture stated. Even when we employ a pepsin material in this process the am nt of th pepsin terial, in addition to the tryptic material for material may be increased twelveiold without an eflectins the body characteristics of the curd. We desirable results. but where the amount of the prefer to add the rennin to sheet coagulation. material be increased threefold the curd Though pepsin in itself serves also as a coagulant. willlikelybe sobroken downas to destroy the therennlnismuchmbepreisrredinthisruncbody. ltispossibletouselessthanwc. c.o1'a n. and though where new i s d it is n t tryptic material which tests 1:1.666 u. s. P. trypessential t add a th succul t. we preier to sin to each 100 pounds or milk and good results employ the rennin for the coagul ting iunctlon.

per 100 pounds of milk isused. b0 curd knives and brought to a muting temperasentialtcaddrenninsince the pepsinam; with the usual methods. when thecurd has magulgflng agent e m m a m formed sumciently, and the whe tests about ve th em 1 found t to form a w- 0.15% to 0.20% as lactic acid. we then increase a curd as does rennin, nd ven w we em loy t."- the temperature without examine the whey to pepsin we prefer 3,150 to dd rennin to eflg t the from about 110 1'. to 120 P. All this point it coagulation. of n the known m only will be helpful to recall that in prior processes rennin and pepsin have qualities which make the Whey is drained Ofl lm d -t y after the them useful as coalulants in cheese production, Ordinary hine at a temln hl F- to and as used herein the term "coagulating agent" to F. In our process, however, we hange the will include rennin. pepsin, or a mixture or these. Procedure at th point by heating the curd to We have turther discovered that instead of 8 fi temperatum. T mllfl hll s W the rdinary trypsln or encreatin i is t r t prefer to use at this stage, namely F. to us a trypti material which is substantially free F. inhibit the ction of the lactic acid bacteria. It is the further feature oi our im- 0: but. in addition. the heatlnl hell pp to our provement that we find it better to use a tryptic nd of curd. namely. one which is subi enzyme material which is substantially tree of to the action of tryntlc enzym also app to steapsln. We have found that by using a tryptic use profound changes in the curd which bematerial substantially tree 0! steapsin we avoi come evident durins the short agins period. an obiection which may best be described by the 1 The curd is normally kept tor about ten minterm sliiht rancidity," and we therefore emphautes at about 110 F. to 120' l". and thereafter side the use oi a tryptlc enzyme material which we draw the whey. We permit the curd to mat is substantially tree 01 steapsin. Normally the after withdrawal of the w and then out the common trypsln or pancreatin might be regarded curd into blocks or slabs. These slabs may be as substantially tree oi steapsin since so little placed in a cooler at about 35' it, and held at this acme-re parable-to that hitherto obtained only after weeks of aging.

By body characteristics we refer to theconsistency, firmness, or substance of the cheese. A well-bodied cheese will feel firm and smooth as distinguished from "pasty. mealy," "crumbly," etc., these evidences of body being well known to the cheese-making trade. Body'characteristics can be identified by melting the card; and a curd which upon application of heat, and with the usual ralt added, will melt to form a smooth, free-flowing mass as distinguished from a stringy, ropy, or solid mass has fully developed body characteristics.

After the expiration of the short aging period the curd is heated to a temperature sufllciently high to destroy the added tryptic enzymes, and such temperature will be not less than about 130 F. Usually we heat the curd to about 150 F. or 160 Ft, since the higher temperatures makes the cheese more fluid and easier to pour from the heating vessel. If desired, the temperatures may be carried to 175 F. or even higher, without damage to the cheese. We have found, however, that if the temperature or the cheese is carried to not less than 130 F. that the activity of the added tryptic enzymes is substantially destroyed. In our customary practice of this part of. the process we had an ordinary emulsifier such as sodium citrate, heat the curd in a suitable vessel to about 130 F. to 160 F., add salt and other desired condiments, then pour the molten cheese into suitable container or packages and allow it to cool. Conveniently other prepared cheeses may be melted with the cheese prepared by this improved process, this other cheese being melted and blended in at this final heating step. Thus our process lends itself very effectively to blending with other cheeses.

As a result of our discoveries we are able to make a cheese having fully aged characteristics. particularly as regards to body, and having a satisfactory flavor, within two or three days from the time the milk is inoculated, a tremendous saving of time when compared with the many months that must elapse in prior processes. Moreover, our invention can be used with raw milk or pasteurized milk, and this is an added advantage.

In the improved process we find it very advantageous to hold the curd during the short aging period at relatively low temperatures. preferably from 30 F. to 50 F. This lower temperature permits of easier control of the tryptic enzyme action and helps in the production of a. uniform cheese having precisely the desired body. In addition, the lower holding temperatures at this stage or the process serve to inhibit the activity of any acid-forming bacteria which escape destruction by the prior heating step so that these bacteria, then in relatively small numbers, will have no opportunity to become active and multiply. Thus it appears that the lower holding temperatures operate discriminantly against the acid-forming bacteria. The heating of the card and whey at a temperature of i'rom 1". to l'. is eflective to inhibit the action or the acid-forming organisms and heat shock them into inactivity. while the subsequent lower holding temperatures are believed to prevent the revival to activity of such organisms as may survive the heating step.

Though in the foregoing explanation theories have been advanced which are now believed to .be corrected. we do not wish to be understood as disclaiming any part or the invention should it later be round that the improved results are best explained in some other way.

Although we have given in the above example certain specific quantities yielding good results. we wish itunderstood that these quantities can b modified without departing from the scope f our invention. The heating period during which the curd and whey is maintained, preterably at 110 F. to 120 R, will ordinarily be of the order of five to ili'teen minutes, but this time may vary depending upon the quantity of milk. the temperatures used. etc.

What we claim as new and desire to secure by Letters Patent is: A

1. In a process for preparing cheese, the steps or adding to a milk material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material to the milk material for developing body characteristics, adding a coagulating agent to said milk material while in uncoagulated state to coagulate it and produce a curd, heating the curd to a temperature or from 106 F. to 128 F. to inhibit further action of said organism and enhance action or said enzyme, and after said enzyme has acted to develop body characteristics. heating the curd to a temperature in excess of F. to destroy said enzyme.

2. In a process for preparing cheese, the steps of adding to a milk material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material to the milk material for developing body characteristics, adding a coagulating agent to said milk material while in uncoagulated state to coagulate it and produce a curd, heating the curd to a temperature of from 110 F. to 120 F. to inhibit further action of said organism and enhance action of said enzyme, and after said enzyme has acted to develop body characteristics. heating the curd to a temperature in excess of 130 F. to destroy said enzyme.

3. In a process for preparing cheese, the steps 01' adding to a milk material a heat sensitive lactic acid developing organism, adding a. tryptic enzyme material to the milk material for developing body characteristics, adding a coagulating agent to said milk material while in uncoagulated state to coagulate it and produce curd and whey, heating the curd in the presence or the whey to a temperature of 106 F. to 128 F. to inhibit fur-- ther action or said organism and enhance action of said enzymes, drawing the whey from the curd. and after said enzymes have acted to develop body characteristics, heating the curd to a temperature in excess of 130 F. to destroy said enzymes.

4. A process as set forth in claim 1 in which said tryptic enzyme material is substantially free of steapsin.

5. In a process for preparing cheese, the steps or adding to a milk material a heat sensitive lactic acid developing organism, adding a. tryptic enzyme material and peptic material to the milk material for developing body characteristics, adding a coagulating agent to said milk material while in uncoasulated state to coagulate it and produce a curd. heating the curd to a temperature of irom 106 F. to 128 1''. to inhibit further action or said organism and enhance action or said enzymes, and after said enzymes have acted to develop hody characteristics. heating the curd to a temperature in excess at 130 F. to destroy said enzymes.

0. In a process for preparing cheese, the steps adding to a milk'material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material which is substantially free oi steapsin and also a pepsin material to the milk material for developing body characteristics, adding a rennin to said milk material while in coagulated state to coagulate it and produce a curd, heating the curd to a temperature oi from 106 F. to 125 If. to inhibit further action 0! said organism and enhance action of said enzymes, and after said enzymes have acted to develop body characteristics heating the curd to a temperature in excess 0! 180 F. to destroy said enzymes.

'1. A process as set forth in claim 6 in which the curd is heated to a temperature at from 110 1'. to 120 F. to inhibit further action of said organism and enhance action of said enzymes.

8. In a process for preparing cheese, the steps of adding to a milk material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material to the milk material !or devel- 3o acme-7e oping body characteristics, adding rennin to said milk material while in coagulated state to coagulate it and produce curd and whey, heating the curdinthe oithewheytoatemperature of from I". to F. to inhibit further action or said organism and enhance action of said enzymes, draining the whey from the curd. and alter the enzymes 0! said tryptic material have acted to develop body characteristics heatin: the curd to a temperature in excess o! 1". to destroy the tryptic enzymes.

9. In a process for preparing cheese, the steps 0! adding to a milk material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material which is substantially free of steapsin to said milk material while in uncoagulated state ior developing body characteristics. adding rennin to the milk to coagulate it and produce curd and whey. heating the curd in the presence 0! the whey to a temperature 0! from 110' l". to 120 1". to inhibit further action of said organism and enhance action of said enzymes, draining the whey from the curd, storing the curd during a further aging period at a temperature of from 30 F. to 50 F., and after said enzymes have acted to develop body characteristics heating the curd to a temperature in excess of 130 1". to destroy said enzymes.

ZOLA D. RDUNDY. HAVARD L. KlIlL.

GBRi'IFI GATE OF COMO]! Patent so. 2,570,879.

March 6, 1915.

ZQIA D. IDURDY, 3'1 AL.

It is hereby certified that error appears in the printed. specification of the above numbered patent requiring correction as and second colmnn, line 2-5,- claim "coagulated read --unooagn1ated--; and that the said Letters Patent should column, line 15-16, claim 6,

to 11m Page is, first 8, for

be read with this correction therein that the same may coni'cm to the record of the case in ihe Patent Office.

Signed and sealed this 19th day or June; A. n.

( Seal) Leslie Frazer Acting Commissioner of Patents.

while in uncoasulated state to coagulate it and produce a curd. heating the curd to a temperature of irom 106 F. to 128 1''. to inhibit further action or said organism and enhance action or said enzymes, and after said enzymes have acted to develop hody characteristics. heating the curd to a temperature in excess at 130 F. to destroy said enzymes.

0. In a process for preparing cheese, the steps adding to a milk'material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material which is substantially free oi steapsin and also a pepsin material to the milk material for developing body characteristics, adding a rennin to said milk material while in coagulated state to coagulate it and produce a curd, heating the curd to a temperature oi from 106 F. to 125 If. to inhibit further action 0! said organism and enhance action of said enzymes, and after said enzymes have acted to develop body characteristics heating the curd to a temperature in excess 0! 180 F. to destroy said enzymes.

'1. A process as set forth in claim 6 in which the curd is heated to a temperature at from 110 1'. to 120 F. to inhibit further action of said organism and enhance action of said enzymes.

8. In a process for preparing cheese, the steps of adding to a milk material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material to the milk material !or devel- 3o acme-7e oping body characteristics, adding rennin to said milk material while in coagulated state to coagulate it and produce curd and whey, heating the curdinthe oithewheytoatemperature of from I". to F. to inhibit further action or said organism and enhance action of said enzymes, draining the whey from the curd. and alter the enzymes 0! said tryptic material have acted to develop body characteristics heatin: the curd to a temperature in excess o! 1". to destroy the tryptic enzymes.

9. In a process for preparing cheese, the steps 0! adding to a milk material a heat sensitive lactic acid developing organism, adding a tryptic enzyme material which is substantially free of steapsin to said milk material while in uncoagulated state ior developing body characteristics. adding rennin to the milk to coagulate it and produce curd and whey. heating the curd in the presence 0! the whey to a temperature 0! from 110' l". to 120 1". to inhibit further action of said organism and enhance action of said enzymes, draining the whey from the curd, storing the curd during a further aging period at a temperature of from 30 F. to 50 F., and after said enzymes have acted to develop body characteristics heating the curd to a temperature in excess of 130 1". to destroy said enzymes.

ZOLA D. RDUNDY. HAVARD L. KlIlL.

GBRi'IFI GATE OF COMO]! Patent so. 2,570,879.

March 6, 1915.

ZQIA D. IDURDY, 3'1 AL.

It is hereby certified that error appears in the printed. specification of the above numbered patent requiring correction as and second colmnn, line 2-5,- claim "coagulated read --unooagn1ated--; and that the said Letters Patent should column, line 15-16, claim 6,

to 11m Page is, first 8, for

be read with this correction therein that the same may coni'cm to the record of the case in ihe Patent Office.

Signed and sealed this 19th day or June; A. n.

( Seal) Leslie Frazer Acting Commissioner of Patents. 

